915 lines
		
	
	
		
			21 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			915 lines
		
	
	
		
			21 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * DECnet       An implementation of the DECnet protocol suite for the LINUX
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|  *              operating system.  DECnet is implemented using the  BSD Socket
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|  *              interface as the means of communication with the user level.
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|  *
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|  *              DECnet Network Services Protocol (Input)
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|  *
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|  * Author:      Eduardo Marcelo Serrat <emserrat@geocities.com>
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|  *
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|  * Changes:
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|  *
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|  *    Steve Whitehouse:  Split into dn_nsp_in.c and dn_nsp_out.c from
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|  *                       original dn_nsp.c.
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|  *    Steve Whitehouse:  Updated to work with my new routing architecture.
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|  *    Steve Whitehouse:  Add changes from Eduardo Serrat's patches.
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|  *    Steve Whitehouse:  Put all ack handling code in a common routine.
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|  *    Steve Whitehouse:  Put other common bits into dn_nsp_rx()
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|  *    Steve Whitehouse:  More checks on skb->len to catch bogus packets
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|  *                       Fixed various race conditions and possible nasties.
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|  *    Steve Whitehouse:  Now handles returned conninit frames.
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|  *     David S. Miller:  New socket locking
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|  *    Steve Whitehouse:  Fixed lockup when socket filtering was enabled.
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|  *         Paul Koning:  Fix to push CC sockets into RUN when acks are
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|  *                       received.
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|  *    Steve Whitehouse:
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|  *   Patrick Caulfield:  Checking conninits for correctness & sending of error
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|  *                       responses.
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|  *    Steve Whitehouse:  Added backlog congestion level return codes.
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|  *   Patrick Caulfield:
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|  *    Steve Whitehouse:  Added flow control support (outbound)
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|  *    Steve Whitehouse:  Prepare for nonlinear skbs
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|  */
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| 
 | |
| /******************************************************************************
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|     (c) 1995-1998 E.M. Serrat		emserrat@geocities.com
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| 
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|     This program is free software; you can redistribute it and/or modify
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|     it under the terms of the GNU General Public License as published by
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|     the Free Software Foundation; either version 2 of the License, or
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|     any later version.
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| 
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|     This program is distributed in the hope that it will be useful,
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|     but WITHOUT ANY WARRANTY; without even the implied warranty of
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|     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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|     GNU General Public License for more details.
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| *******************************************************************************/
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| 
 | |
| #include <linux/errno.h>
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| #include <linux/types.h>
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| #include <linux/socket.h>
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| #include <linux/in.h>
 | |
| #include <linux/kernel.h>
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| #include <linux/timer.h>
 | |
| #include <linux/string.h>
 | |
| #include <linux/sockios.h>
 | |
| #include <linux/net.h>
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| #include <linux/netdevice.h>
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| #include <linux/inet.h>
 | |
| #include <linux/route.h>
 | |
| #include <linux/slab.h>
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| #include <net/sock.h>
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| #include <net/tcp_states.h>
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| #include <linux/fcntl.h>
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| #include <linux/mm.h>
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| #include <linux/termios.h>
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| #include <linux/interrupt.h>
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| #include <linux/proc_fs.h>
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| #include <linux/stat.h>
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| #include <linux/init.h>
 | |
| #include <linux/poll.h>
 | |
| #include <linux/netfilter_decnet.h>
 | |
| #include <net/neighbour.h>
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| #include <net/dst.h>
 | |
| #include <net/dn.h>
 | |
| #include <net/dn_nsp.h>
 | |
| #include <net/dn_dev.h>
 | |
| #include <net/dn_route.h>
 | |
| 
 | |
| extern int decnet_log_martians;
 | |
| 
 | |
| static void dn_log_martian(struct sk_buff *skb, const char *msg)
 | |
| {
 | |
| 	if (decnet_log_martians) {
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| 		char *devname = skb->dev ? skb->dev->name : "???";
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| 		struct dn_skb_cb *cb = DN_SKB_CB(skb);
 | |
| 		net_info_ratelimited("DECnet: Martian packet (%s) dev=%s src=0x%04hx dst=0x%04hx srcport=0x%04hx dstport=0x%04hx\n",
 | |
| 				     msg, devname,
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| 				     le16_to_cpu(cb->src),
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| 				     le16_to_cpu(cb->dst),
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| 				     le16_to_cpu(cb->src_port),
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| 				     le16_to_cpu(cb->dst_port));
 | |
| 	}
 | |
| }
 | |
| 
 | |
| /*
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|  * For this function we've flipped the cross-subchannel bit
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|  * if the message is an otherdata or linkservice message. Thus
 | |
|  * we can use it to work out what to update.
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|  */
 | |
| static void dn_ack(struct sock *sk, struct sk_buff *skb, unsigned short ack)
 | |
| {
 | |
| 	struct dn_scp *scp = DN_SK(sk);
 | |
| 	unsigned short type = ((ack >> 12) & 0x0003);
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| 	int wakeup = 0;
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| 
 | |
| 	switch (type) {
 | |
| 	case 0: /* ACK - Data */
 | |
| 		if (dn_after(ack, scp->ackrcv_dat)) {
 | |
| 			scp->ackrcv_dat = ack & 0x0fff;
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| 			wakeup |= dn_nsp_check_xmit_queue(sk, skb,
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| 							  &scp->data_xmit_queue,
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| 							  ack);
 | |
| 		}
 | |
| 		break;
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| 	case 1: /* NAK - Data */
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| 		break;
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| 	case 2: /* ACK - OtherData */
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| 		if (dn_after(ack, scp->ackrcv_oth)) {
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| 			scp->ackrcv_oth = ack & 0x0fff;
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| 			wakeup |= dn_nsp_check_xmit_queue(sk, skb,
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| 							  &scp->other_xmit_queue,
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| 							  ack);
 | |
| 		}
 | |
| 		break;
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| 	case 3: /* NAK - OtherData */
 | |
| 		break;
 | |
| 	}
 | |
| 
 | |
| 	if (wakeup && !sock_flag(sk, SOCK_DEAD))
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| 		sk->sk_state_change(sk);
 | |
| }
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| 
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| /*
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|  * This function is a universal ack processor.
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|  */
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| static int dn_process_ack(struct sock *sk, struct sk_buff *skb, int oth)
 | |
| {
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| 	__le16 *ptr = (__le16 *)skb->data;
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| 	int len = 0;
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| 	unsigned short ack;
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| 
 | |
| 	if (skb->len < 2)
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| 		return len;
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| 
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| 	if ((ack = le16_to_cpu(*ptr)) & 0x8000) {
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| 		skb_pull(skb, 2);
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| 		ptr++;
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| 		len += 2;
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| 		if ((ack & 0x4000) == 0) {
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| 			if (oth)
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| 				ack ^= 0x2000;
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| 			dn_ack(sk, skb, ack);
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| 		}
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| 	}
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| 
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| 	if (skb->len < 2)
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| 		return len;
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| 
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| 	if ((ack = le16_to_cpu(*ptr)) & 0x8000) {
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| 		skb_pull(skb, 2);
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| 		len += 2;
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| 		if ((ack & 0x4000) == 0) {
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| 			if (oth)
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| 				ack ^= 0x2000;
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| 			dn_ack(sk, skb, ack);
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| 		}
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| 	}
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| 
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| 	return len;
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| }
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| 
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| 
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| /**
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|  * dn_check_idf - Check an image data field format is correct.
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|  * @pptr: Pointer to pointer to image data
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|  * @len: Pointer to length of image data
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|  * @max: The maximum allowed length of the data in the image data field
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|  * @follow_on: Check that this many bytes exist beyond the end of the image data
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|  *
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|  * Returns: 0 if ok, -1 on error
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|  */
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| static inline int dn_check_idf(unsigned char **pptr, int *len, unsigned char max, unsigned char follow_on)
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| {
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| 	unsigned char *ptr = *pptr;
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| 	unsigned char flen = *ptr++;
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| 
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| 	(*len)--;
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| 	if (flen > max)
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| 		return -1;
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| 	if ((flen + follow_on) > *len)
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| 		return -1;
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| 
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| 	*len -= flen;
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| 	*pptr = ptr + flen;
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| 	return 0;
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| }
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| 
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| /*
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|  * Table of reason codes to pass back to node which sent us a badly
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|  * formed message, plus text messages for the log. A zero entry in
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|  * the reason field means "don't reply" otherwise a disc init is sent with
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|  * the specified reason code.
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|  */
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| static struct {
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| 	unsigned short reason;
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| 	const char *text;
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| } ci_err_table[] = {
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|  { 0,             "CI: Truncated message" },
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|  { NSP_REASON_ID, "CI: Destination username error" },
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|  { NSP_REASON_ID, "CI: Destination username type" },
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|  { NSP_REASON_US, "CI: Source username error" },
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|  { 0,             "CI: Truncated at menuver" },
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|  { 0,             "CI: Truncated before access or user data" },
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|  { NSP_REASON_IO, "CI: Access data format error" },
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|  { NSP_REASON_IO, "CI: User data format error" }
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| };
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| 
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| /*
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|  * This function uses a slightly different lookup method
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|  * to find its sockets, since it searches on object name/number
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|  * rather than port numbers. Various tests are done to ensure that
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|  * the incoming data is in the correct format before it is queued to
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|  * a socket.
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|  */
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| static struct sock *dn_find_listener(struct sk_buff *skb, unsigned short *reason)
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| {
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| 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
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| 	struct nsp_conn_init_msg *msg = (struct nsp_conn_init_msg *)skb->data;
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| 	struct sockaddr_dn dstaddr;
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| 	struct sockaddr_dn srcaddr;
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| 	unsigned char type = 0;
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| 	int dstlen;
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| 	int srclen;
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| 	unsigned char *ptr;
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| 	int len;
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| 	int err = 0;
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| 	unsigned char menuver;
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| 
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| 	memset(&dstaddr, 0, sizeof(struct sockaddr_dn));
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| 	memset(&srcaddr, 0, sizeof(struct sockaddr_dn));
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| 
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| 	/*
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| 	 * 1. Decode & remove message header
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| 	 */
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| 	cb->src_port = msg->srcaddr;
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| 	cb->dst_port = msg->dstaddr;
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| 	cb->services = msg->services;
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| 	cb->info     = msg->info;
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| 	cb->segsize  = le16_to_cpu(msg->segsize);
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| 
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| 	if (!pskb_may_pull(skb, sizeof(*msg)))
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| 		goto err_out;
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| 
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| 	skb_pull(skb, sizeof(*msg));
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| 
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| 	len = skb->len;
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| 	ptr = skb->data;
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| 
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| 	/*
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| 	 * 2. Check destination end username format
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| 	 */
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| 	dstlen = dn_username2sockaddr(ptr, len, &dstaddr, &type);
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| 	err++;
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| 	if (dstlen < 0)
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| 		goto err_out;
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| 
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| 	err++;
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| 	if (type > 1)
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| 		goto err_out;
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| 
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| 	len -= dstlen;
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| 	ptr += dstlen;
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| 
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| 	/*
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| 	 * 3. Check source end username format
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| 	 */
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| 	srclen = dn_username2sockaddr(ptr, len, &srcaddr, &type);
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| 	err++;
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| 	if (srclen < 0)
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| 		goto err_out;
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| 
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| 	len -= srclen;
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| 	ptr += srclen;
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| 	err++;
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| 	if (len < 1)
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| 		goto err_out;
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| 
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| 	menuver = *ptr;
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| 	ptr++;
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| 	len--;
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| 
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| 	/*
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| 	 * 4. Check that optional data actually exists if menuver says it does
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| 	 */
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| 	err++;
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| 	if ((menuver & (DN_MENUVER_ACC | DN_MENUVER_USR)) && (len < 1))
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| 		goto err_out;
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| 
 | |
| 	/*
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| 	 * 5. Check optional access data format
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| 	 */
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| 	err++;
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| 	if (menuver & DN_MENUVER_ACC) {
 | |
| 		if (dn_check_idf(&ptr, &len, 39, 1))
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| 			goto err_out;
 | |
| 		if (dn_check_idf(&ptr, &len, 39, 1))
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| 			goto err_out;
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| 		if (dn_check_idf(&ptr, &len, 39, (menuver & DN_MENUVER_USR) ? 1 : 0))
 | |
| 			goto err_out;
 | |
| 	}
 | |
| 
 | |
| 	/*
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| 	 * 6. Check optional user data format
 | |
| 	 */
 | |
| 	err++;
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| 	if (menuver & DN_MENUVER_USR) {
 | |
| 		if (dn_check_idf(&ptr, &len, 16, 0))
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| 			goto err_out;
 | |
| 	}
 | |
| 
 | |
| 	/*
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| 	 * 7. Look up socket based on destination end username
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| 	 */
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| 	return dn_sklist_find_listener(&dstaddr);
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| err_out:
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| 	dn_log_martian(skb, ci_err_table[err].text);
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| 	*reason = ci_err_table[err].reason;
 | |
| 	return NULL;
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| }
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| 
 | |
| 
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| static void dn_nsp_conn_init(struct sock *sk, struct sk_buff *skb)
 | |
| {
 | |
| 	if (sk_acceptq_is_full(sk)) {
 | |
| 		kfree_skb(skb);
 | |
| 		return;
 | |
| 	}
 | |
| 
 | |
| 	sk_acceptq_added(sk);
 | |
| 	skb_queue_tail(&sk->sk_receive_queue, skb);
 | |
| 	sk->sk_state_change(sk);
 | |
| }
 | |
| 
 | |
| static void dn_nsp_conn_conf(struct sock *sk, struct sk_buff *skb)
 | |
| {
 | |
| 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
 | |
| 	struct dn_scp *scp = DN_SK(sk);
 | |
| 	unsigned char *ptr;
 | |
| 
 | |
| 	if (skb->len < 4)
 | |
| 		goto out;
 | |
| 
 | |
| 	ptr = skb->data;
 | |
| 	cb->services = *ptr++;
 | |
| 	cb->info = *ptr++;
 | |
| 	cb->segsize = le16_to_cpu(*(__le16 *)ptr);
 | |
| 
 | |
| 	if ((scp->state == DN_CI) || (scp->state == DN_CD)) {
 | |
| 		scp->persist = 0;
 | |
| 		scp->addrrem = cb->src_port;
 | |
| 		sk->sk_state = TCP_ESTABLISHED;
 | |
| 		scp->state = DN_RUN;
 | |
| 		scp->services_rem = cb->services;
 | |
| 		scp->info_rem = cb->info;
 | |
| 		scp->segsize_rem = cb->segsize;
 | |
| 
 | |
| 		if ((scp->services_rem & NSP_FC_MASK) == NSP_FC_NONE)
 | |
| 			scp->max_window = decnet_no_fc_max_cwnd;
 | |
| 
 | |
| 		if (skb->len > 0) {
 | |
| 			u16 dlen = *skb->data;
 | |
| 			if ((dlen <= 16) && (dlen <= skb->len)) {
 | |
| 				scp->conndata_in.opt_optl = cpu_to_le16(dlen);
 | |
| 				skb_copy_from_linear_data_offset(skb, 1,
 | |
| 					      scp->conndata_in.opt_data, dlen);
 | |
| 			}
 | |
| 		}
 | |
| 		dn_nsp_send_link(sk, DN_NOCHANGE, 0);
 | |
| 		if (!sock_flag(sk, SOCK_DEAD))
 | |
| 			sk->sk_state_change(sk);
 | |
| 	}
 | |
| 
 | |
| out:
 | |
| 	kfree_skb(skb);
 | |
| }
 | |
| 
 | |
| static void dn_nsp_conn_ack(struct sock *sk, struct sk_buff *skb)
 | |
| {
 | |
| 	struct dn_scp *scp = DN_SK(sk);
 | |
| 
 | |
| 	if (scp->state == DN_CI) {
 | |
| 		scp->state = DN_CD;
 | |
| 		scp->persist = 0;
 | |
| 	}
 | |
| 
 | |
| 	kfree_skb(skb);
 | |
| }
 | |
| 
 | |
| static void dn_nsp_disc_init(struct sock *sk, struct sk_buff *skb)
 | |
| {
 | |
| 	struct dn_scp *scp = DN_SK(sk);
 | |
| 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
 | |
| 	unsigned short reason;
 | |
| 
 | |
| 	if (skb->len < 2)
 | |
| 		goto out;
 | |
| 
 | |
| 	reason = le16_to_cpu(*(__le16 *)skb->data);
 | |
| 	skb_pull(skb, 2);
 | |
| 
 | |
| 	scp->discdata_in.opt_status = cpu_to_le16(reason);
 | |
| 	scp->discdata_in.opt_optl   = 0;
 | |
| 	memset(scp->discdata_in.opt_data, 0, 16);
 | |
| 
 | |
| 	if (skb->len > 0) {
 | |
| 		u16 dlen = *skb->data;
 | |
| 		if ((dlen <= 16) && (dlen <= skb->len)) {
 | |
| 			scp->discdata_in.opt_optl = cpu_to_le16(dlen);
 | |
| 			skb_copy_from_linear_data_offset(skb, 1, scp->discdata_in.opt_data, dlen);
 | |
| 		}
 | |
| 	}
 | |
| 
 | |
| 	scp->addrrem = cb->src_port;
 | |
| 	sk->sk_state = TCP_CLOSE;
 | |
| 
 | |
| 	switch (scp->state) {
 | |
| 	case DN_CI:
 | |
| 	case DN_CD:
 | |
| 		scp->state = DN_RJ;
 | |
| 		sk->sk_err = ECONNREFUSED;
 | |
| 		break;
 | |
| 	case DN_RUN:
 | |
| 		sk->sk_shutdown |= SHUTDOWN_MASK;
 | |
| 		scp->state = DN_DN;
 | |
| 		break;
 | |
| 	case DN_DI:
 | |
| 		scp->state = DN_DIC;
 | |
| 		break;
 | |
| 	}
 | |
| 
 | |
| 	if (!sock_flag(sk, SOCK_DEAD)) {
 | |
| 		if (sk->sk_socket->state != SS_UNCONNECTED)
 | |
| 			sk->sk_socket->state = SS_DISCONNECTING;
 | |
| 		sk->sk_state_change(sk);
 | |
| 	}
 | |
| 
 | |
| 	/*
 | |
| 	 * It appears that its possible for remote machines to send disc
 | |
| 	 * init messages with no port identifier if we are in the CI and
 | |
| 	 * possibly also the CD state. Obviously we shouldn't reply with
 | |
| 	 * a message if we don't know what the end point is.
 | |
| 	 */
 | |
| 	if (scp->addrrem) {
 | |
| 		dn_nsp_send_disc(sk, NSP_DISCCONF, NSP_REASON_DC, GFP_ATOMIC);
 | |
| 	}
 | |
| 	scp->persist_fxn = dn_destroy_timer;
 | |
| 	scp->persist = dn_nsp_persist(sk);
 | |
| 
 | |
| out:
 | |
| 	kfree_skb(skb);
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * disc_conf messages are also called no_resources or no_link
 | |
|  * messages depending upon the "reason" field.
 | |
|  */
 | |
| static void dn_nsp_disc_conf(struct sock *sk, struct sk_buff *skb)
 | |
| {
 | |
| 	struct dn_scp *scp = DN_SK(sk);
 | |
| 	unsigned short reason;
 | |
| 
 | |
| 	if (skb->len != 2)
 | |
| 		goto out;
 | |
| 
 | |
| 	reason = le16_to_cpu(*(__le16 *)skb->data);
 | |
| 
 | |
| 	sk->sk_state = TCP_CLOSE;
 | |
| 
 | |
| 	switch (scp->state) {
 | |
| 	case DN_CI:
 | |
| 		scp->state = DN_NR;
 | |
| 		break;
 | |
| 	case DN_DR:
 | |
| 		if (reason == NSP_REASON_DC)
 | |
| 			scp->state = DN_DRC;
 | |
| 		if (reason == NSP_REASON_NL)
 | |
| 			scp->state = DN_CN;
 | |
| 		break;
 | |
| 	case DN_DI:
 | |
| 		scp->state = DN_DIC;
 | |
| 		break;
 | |
| 	case DN_RUN:
 | |
| 		sk->sk_shutdown |= SHUTDOWN_MASK;
 | |
| 	case DN_CC:
 | |
| 		scp->state = DN_CN;
 | |
| 	}
 | |
| 
 | |
| 	if (!sock_flag(sk, SOCK_DEAD)) {
 | |
| 		if (sk->sk_socket->state != SS_UNCONNECTED)
 | |
| 			sk->sk_socket->state = SS_DISCONNECTING;
 | |
| 		sk->sk_state_change(sk);
 | |
| 	}
 | |
| 
 | |
| 	scp->persist_fxn = dn_destroy_timer;
 | |
| 	scp->persist = dn_nsp_persist(sk);
 | |
| 
 | |
| out:
 | |
| 	kfree_skb(skb);
 | |
| }
 | |
| 
 | |
| static void dn_nsp_linkservice(struct sock *sk, struct sk_buff *skb)
 | |
| {
 | |
| 	struct dn_scp *scp = DN_SK(sk);
 | |
| 	unsigned short segnum;
 | |
| 	unsigned char lsflags;
 | |
| 	signed char fcval;
 | |
| 	int wake_up = 0;
 | |
| 	char *ptr = skb->data;
 | |
| 	unsigned char fctype = scp->services_rem & NSP_FC_MASK;
 | |
| 
 | |
| 	if (skb->len != 4)
 | |
| 		goto out;
 | |
| 
 | |
| 	segnum = le16_to_cpu(*(__le16 *)ptr);
 | |
| 	ptr += 2;
 | |
| 	lsflags = *(unsigned char *)ptr++;
 | |
| 	fcval = *ptr;
 | |
| 
 | |
| 	/*
 | |
| 	 * Here we ignore erronous packets which should really
 | |
| 	 * should cause a connection abort. It is not critical
 | |
| 	 * for now though.
 | |
| 	 */
 | |
| 	if (lsflags & 0xf8)
 | |
| 		goto out;
 | |
| 
 | |
| 	if (seq_next(scp->numoth_rcv, segnum)) {
 | |
| 		seq_add(&scp->numoth_rcv, 1);
 | |
| 		switch(lsflags & 0x04) { /* FCVAL INT */
 | |
| 		case 0x00: /* Normal Request */
 | |
| 			switch(lsflags & 0x03) { /* FCVAL MOD */
 | |
| 			case 0x00: /* Request count */
 | |
| 				if (fcval < 0) {
 | |
| 					unsigned char p_fcval = -fcval;
 | |
| 					if ((scp->flowrem_dat > p_fcval) &&
 | |
| 					    (fctype == NSP_FC_SCMC)) {
 | |
| 						scp->flowrem_dat -= p_fcval;
 | |
| 					}
 | |
| 				} else if (fcval > 0) {
 | |
| 					scp->flowrem_dat += fcval;
 | |
| 					wake_up = 1;
 | |
| 				}
 | |
| 				break;
 | |
| 			case 0x01: /* Stop outgoing data */
 | |
| 				scp->flowrem_sw = DN_DONTSEND;
 | |
| 				break;
 | |
| 			case 0x02: /* Ok to start again */
 | |
| 				scp->flowrem_sw = DN_SEND;
 | |
| 				dn_nsp_output(sk);
 | |
| 				wake_up = 1;
 | |
| 			}
 | |
| 			break;
 | |
| 		case 0x04: /* Interrupt Request */
 | |
| 			if (fcval > 0) {
 | |
| 				scp->flowrem_oth += fcval;
 | |
| 				wake_up = 1;
 | |
| 			}
 | |
| 			break;
 | |
| 		}
 | |
| 		if (wake_up && !sock_flag(sk, SOCK_DEAD))
 | |
| 			sk->sk_state_change(sk);
 | |
| 	}
 | |
| 
 | |
| 	dn_nsp_send_oth_ack(sk);
 | |
| 
 | |
| out:
 | |
| 	kfree_skb(skb);
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Copy of sock_queue_rcv_skb (from sock.h) without
 | |
|  * bh_lock_sock() (its already held when this is called) which
 | |
|  * also allows data and other data to be queued to a socket.
 | |
|  */
 | |
| static __inline__ int dn_queue_skb(struct sock *sk, struct sk_buff *skb, int sig, struct sk_buff_head *queue)
 | |
| {
 | |
| 	int err;
 | |
| 
 | |
| 	/* Cast skb->rcvbuf to unsigned... It's pointless, but reduces
 | |
| 	   number of warnings when compiling with -W --ANK
 | |
| 	 */
 | |
| 	if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
 | |
| 	    (unsigned int)sk->sk_rcvbuf) {
 | |
| 		err = -ENOMEM;
 | |
| 		goto out;
 | |
| 	}
 | |
| 
 | |
| 	err = sk_filter(sk, skb);
 | |
| 	if (err)
 | |
| 		goto out;
 | |
| 
 | |
| 	skb_set_owner_r(skb, sk);
 | |
| 	skb_queue_tail(queue, skb);
 | |
| 
 | |
| 	if (!sock_flag(sk, SOCK_DEAD))
 | |
| 		sk->sk_data_ready(sk);
 | |
| out:
 | |
| 	return err;
 | |
| }
 | |
| 
 | |
| static void dn_nsp_otherdata(struct sock *sk, struct sk_buff *skb)
 | |
| {
 | |
| 	struct dn_scp *scp = DN_SK(sk);
 | |
| 	unsigned short segnum;
 | |
| 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
 | |
| 	int queued = 0;
 | |
| 
 | |
| 	if (skb->len < 2)
 | |
| 		goto out;
 | |
| 
 | |
| 	cb->segnum = segnum = le16_to_cpu(*(__le16 *)skb->data);
 | |
| 	skb_pull(skb, 2);
 | |
| 
 | |
| 	if (seq_next(scp->numoth_rcv, segnum)) {
 | |
| 
 | |
| 		if (dn_queue_skb(sk, skb, SIGURG, &scp->other_receive_queue) == 0) {
 | |
| 			seq_add(&scp->numoth_rcv, 1);
 | |
| 			scp->other_report = 0;
 | |
| 			queued = 1;
 | |
| 		}
 | |
| 	}
 | |
| 
 | |
| 	dn_nsp_send_oth_ack(sk);
 | |
| out:
 | |
| 	if (!queued)
 | |
| 		kfree_skb(skb);
 | |
| }
 | |
| 
 | |
| static void dn_nsp_data(struct sock *sk, struct sk_buff *skb)
 | |
| {
 | |
| 	int queued = 0;
 | |
| 	unsigned short segnum;
 | |
| 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
 | |
| 	struct dn_scp *scp = DN_SK(sk);
 | |
| 
 | |
| 	if (skb->len < 2)
 | |
| 		goto out;
 | |
| 
 | |
| 	cb->segnum = segnum = le16_to_cpu(*(__le16 *)skb->data);
 | |
| 	skb_pull(skb, 2);
 | |
| 
 | |
| 	if (seq_next(scp->numdat_rcv, segnum)) {
 | |
| 		if (dn_queue_skb(sk, skb, SIGIO, &sk->sk_receive_queue) == 0) {
 | |
| 			seq_add(&scp->numdat_rcv, 1);
 | |
| 			queued = 1;
 | |
| 		}
 | |
| 
 | |
| 		if ((scp->flowloc_sw == DN_SEND) && dn_congested(sk)) {
 | |
| 			scp->flowloc_sw = DN_DONTSEND;
 | |
| 			dn_nsp_send_link(sk, DN_DONTSEND, 0);
 | |
| 		}
 | |
| 	}
 | |
| 
 | |
| 	dn_nsp_send_data_ack(sk);
 | |
| out:
 | |
| 	if (!queued)
 | |
| 		kfree_skb(skb);
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * If one of our conninit messages is returned, this function
 | |
|  * deals with it. It puts the socket into the NO_COMMUNICATION
 | |
|  * state.
 | |
|  */
 | |
| static void dn_returned_conn_init(struct sock *sk, struct sk_buff *skb)
 | |
| {
 | |
| 	struct dn_scp *scp = DN_SK(sk);
 | |
| 
 | |
| 	if (scp->state == DN_CI) {
 | |
| 		scp->state = DN_NC;
 | |
| 		sk->sk_state = TCP_CLOSE;
 | |
| 		if (!sock_flag(sk, SOCK_DEAD))
 | |
| 			sk->sk_state_change(sk);
 | |
| 	}
 | |
| 
 | |
| 	kfree_skb(skb);
 | |
| }
 | |
| 
 | |
| static int dn_nsp_no_socket(struct sk_buff *skb, unsigned short reason)
 | |
| {
 | |
| 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
 | |
| 	int ret = NET_RX_DROP;
 | |
| 
 | |
| 	/* Must not reply to returned packets */
 | |
| 	if (cb->rt_flags & DN_RT_F_RTS)
 | |
| 		goto out;
 | |
| 
 | |
| 	if ((reason != NSP_REASON_OK) && ((cb->nsp_flags & 0x0c) == 0x08)) {
 | |
| 		switch (cb->nsp_flags & 0x70) {
 | |
| 		case 0x10:
 | |
| 		case 0x60: /* (Retransmitted) Connect Init */
 | |
| 			dn_nsp_return_disc(skb, NSP_DISCINIT, reason);
 | |
| 			ret = NET_RX_SUCCESS;
 | |
| 			break;
 | |
| 		case 0x20: /* Connect Confirm */
 | |
| 			dn_nsp_return_disc(skb, NSP_DISCCONF, reason);
 | |
| 			ret = NET_RX_SUCCESS;
 | |
| 			break;
 | |
| 		}
 | |
| 	}
 | |
| 
 | |
| out:
 | |
| 	kfree_skb(skb);
 | |
| 	return ret;
 | |
| }
 | |
| 
 | |
| static int dn_nsp_rx_packet(struct net *net, struct sock *sk2,
 | |
| 			    struct sk_buff *skb)
 | |
| {
 | |
| 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
 | |
| 	struct sock *sk = NULL;
 | |
| 	unsigned char *ptr = (unsigned char *)skb->data;
 | |
| 	unsigned short reason = NSP_REASON_NL;
 | |
| 
 | |
| 	if (!pskb_may_pull(skb, 2))
 | |
| 		goto free_out;
 | |
| 
 | |
| 	skb_reset_transport_header(skb);
 | |
| 	cb->nsp_flags = *ptr++;
 | |
| 
 | |
| 	if (decnet_debug_level & 2)
 | |
| 		printk(KERN_DEBUG "dn_nsp_rx: Message type 0x%02x\n", (int)cb->nsp_flags);
 | |
| 
 | |
| 	if (cb->nsp_flags & 0x83)
 | |
| 		goto free_out;
 | |
| 
 | |
| 	/*
 | |
| 	 * Filter out conninits and useless packet types
 | |
| 	 */
 | |
| 	if ((cb->nsp_flags & 0x0c) == 0x08) {
 | |
| 		switch (cb->nsp_flags & 0x70) {
 | |
| 		case 0x00: /* NOP */
 | |
| 		case 0x70: /* Reserved */
 | |
| 		case 0x50: /* Reserved, Phase II node init */
 | |
| 			goto free_out;
 | |
| 		case 0x10:
 | |
| 		case 0x60:
 | |
| 			if (unlikely(cb->rt_flags & DN_RT_F_RTS))
 | |
| 				goto free_out;
 | |
| 			sk = dn_find_listener(skb, &reason);
 | |
| 			goto got_it;
 | |
| 		}
 | |
| 	}
 | |
| 
 | |
| 	if (!pskb_may_pull(skb, 3))
 | |
| 		goto free_out;
 | |
| 
 | |
| 	/*
 | |
| 	 * Grab the destination address.
 | |
| 	 */
 | |
| 	cb->dst_port = *(__le16 *)ptr;
 | |
| 	cb->src_port = 0;
 | |
| 	ptr += 2;
 | |
| 
 | |
| 	/*
 | |
| 	 * If not a connack, grab the source address too.
 | |
| 	 */
 | |
| 	if (pskb_may_pull(skb, 5)) {
 | |
| 		cb->src_port = *(__le16 *)ptr;
 | |
| 		ptr += 2;
 | |
| 		skb_pull(skb, 5);
 | |
| 	}
 | |
| 
 | |
| 	/*
 | |
| 	 * Returned packets...
 | |
| 	 * Swap src & dst and look up in the normal way.
 | |
| 	 */
 | |
| 	if (unlikely(cb->rt_flags & DN_RT_F_RTS)) {
 | |
| 		swap(cb->dst_port, cb->src_port);
 | |
| 		swap(cb->dst, cb->src);
 | |
| 	}
 | |
| 
 | |
| 	/*
 | |
| 	 * Find the socket to which this skb is destined.
 | |
| 	 */
 | |
| 	sk = dn_find_by_skb(skb);
 | |
| got_it:
 | |
| 	if (sk != NULL) {
 | |
| 		struct dn_scp *scp = DN_SK(sk);
 | |
| 
 | |
| 		/* Reset backoff */
 | |
| 		scp->nsp_rxtshift = 0;
 | |
| 
 | |
| 		/*
 | |
| 		 * We linearize everything except data segments here.
 | |
| 		 */
 | |
| 		if (cb->nsp_flags & ~0x60) {
 | |
| 			if (unlikely(skb_linearize(skb)))
 | |
| 				goto free_out;
 | |
| 		}
 | |
| 
 | |
| 		return sk_receive_skb(sk, skb, 0);
 | |
| 	}
 | |
| 
 | |
| 	return dn_nsp_no_socket(skb, reason);
 | |
| 
 | |
| free_out:
 | |
| 	kfree_skb(skb);
 | |
| 	return NET_RX_DROP;
 | |
| }
 | |
| 
 | |
| int dn_nsp_rx(struct sk_buff *skb)
 | |
| {
 | |
| 	return NF_HOOK(NFPROTO_DECNET, NF_DN_LOCAL_IN,
 | |
| 		       &init_net, NULL, skb, skb->dev, NULL,
 | |
| 		       dn_nsp_rx_packet);
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * This is the main receive routine for sockets. It is called
 | |
|  * from the above when the socket is not busy, and also from
 | |
|  * sock_release() when there is a backlog queued up.
 | |
|  */
 | |
| int dn_nsp_backlog_rcv(struct sock *sk, struct sk_buff *skb)
 | |
| {
 | |
| 	struct dn_scp *scp = DN_SK(sk);
 | |
| 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
 | |
| 
 | |
| 	if (cb->rt_flags & DN_RT_F_RTS) {
 | |
| 		if (cb->nsp_flags == 0x18 || cb->nsp_flags == 0x68)
 | |
| 			dn_returned_conn_init(sk, skb);
 | |
| 		else
 | |
| 			kfree_skb(skb);
 | |
| 		return NET_RX_SUCCESS;
 | |
| 	}
 | |
| 
 | |
| 	/*
 | |
| 	 * Control packet.
 | |
| 	 */
 | |
| 	if ((cb->nsp_flags & 0x0c) == 0x08) {
 | |
| 		switch (cb->nsp_flags & 0x70) {
 | |
| 		case 0x10:
 | |
| 		case 0x60:
 | |
| 			dn_nsp_conn_init(sk, skb);
 | |
| 			break;
 | |
| 		case 0x20:
 | |
| 			dn_nsp_conn_conf(sk, skb);
 | |
| 			break;
 | |
| 		case 0x30:
 | |
| 			dn_nsp_disc_init(sk, skb);
 | |
| 			break;
 | |
| 		case 0x40:
 | |
| 			dn_nsp_disc_conf(sk, skb);
 | |
| 			break;
 | |
| 		}
 | |
| 
 | |
| 	} else if (cb->nsp_flags == 0x24) {
 | |
| 		/*
 | |
| 		 * Special for connacks, 'cos they don't have
 | |
| 		 * ack data or ack otherdata info.
 | |
| 		 */
 | |
| 		dn_nsp_conn_ack(sk, skb);
 | |
| 	} else {
 | |
| 		int other = 1;
 | |
| 
 | |
| 		/* both data and ack frames can kick a CC socket into RUN */
 | |
| 		if ((scp->state == DN_CC) && !sock_flag(sk, SOCK_DEAD)) {
 | |
| 			scp->state = DN_RUN;
 | |
| 			sk->sk_state = TCP_ESTABLISHED;
 | |
| 			sk->sk_state_change(sk);
 | |
| 		}
 | |
| 
 | |
| 		if ((cb->nsp_flags & 0x1c) == 0)
 | |
| 			other = 0;
 | |
| 		if (cb->nsp_flags == 0x04)
 | |
| 			other = 0;
 | |
| 
 | |
| 		/*
 | |
| 		 * Read out ack data here, this applies equally
 | |
| 		 * to data, other data, link serivce and both
 | |
| 		 * ack data and ack otherdata.
 | |
| 		 */
 | |
| 		dn_process_ack(sk, skb, other);
 | |
| 
 | |
| 		/*
 | |
| 		 * If we've some sort of data here then call a
 | |
| 		 * suitable routine for dealing with it, otherwise
 | |
| 		 * the packet is an ack and can be discarded.
 | |
| 		 */
 | |
| 		if ((cb->nsp_flags & 0x0c) == 0) {
 | |
| 
 | |
| 			if (scp->state != DN_RUN)
 | |
| 				goto free_out;
 | |
| 
 | |
| 			switch (cb->nsp_flags) {
 | |
| 			case 0x10: /* LS */
 | |
| 				dn_nsp_linkservice(sk, skb);
 | |
| 				break;
 | |
| 			case 0x30: /* OD */
 | |
| 				dn_nsp_otherdata(sk, skb);
 | |
| 				break;
 | |
| 			default:
 | |
| 				dn_nsp_data(sk, skb);
 | |
| 			}
 | |
| 
 | |
| 		} else { /* Ack, chuck it out here */
 | |
| free_out:
 | |
| 			kfree_skb(skb);
 | |
| 		}
 | |
| 	}
 | |
| 
 | |
| 	return NET_RX_SUCCESS;
 | |
| }
 | |
| 
 |